Process for drying macaroni



May 8, 1951 B. s. SCOTLAND PRocEss FOR DRYING MAC/mom 3 Sheets-Sheet 1 Filed Nov. 1, 1949 May 8, 1951 B. s. scoTLAND PROCESS FOR DRYING MACARONI 3 Sheets-Sheet 2 Filed Nov. l, 1949 B. s. SCOTLAND 2,552,120

PRocEss FOR DRYING MAcARoNI 3 Sheets-Sheet 3 muNWNl @u www iii DJ May 8, 1951 Filed Nov. 1, 1949 Patented May 83, 1,951

UNITED STATES PATENT OFFICE 2,552,120 PROCESS FOR DRYING MAf'lARoNIV Bayard S. Scotland; Joliet, Ill. Application November 1, 1949; Serial No-.\124,897

(Cl. B2i-31)" This invention relates to a new and improved process and apparatus for drying macaroni and other articles from which it is desired to remove moisture.

Drying of macaroni has long been a problem because of the length of time involved. In making macaroni it is extruded from dies when in a moist state throughout. From years of experience men in the macaroni industry have drawn one del'inite conclusion and that is thatmacaroni must be allowed to dry naturallyor it would not be top quality. There have been numerous attempts to speed up the drying of macaroni, but the result has always been a poorer grade of macaroni. Ordinarily macaroni checks and cracks on the application of heat. Thus enormous storage space has been required in order' to carry on the production of macaroni. t

It is therefore a principal object of this invention to effect a relatively quick continuous drying f top qualityV macaroni.

An important object .of this invention is the provision of means in a drying mechanism for preliminarily drying the outer surface of moist macaroni and other articles and thereafter d'riv ing out internal moisture by a succession of passes through ovens and a sweat box. l

AnotherA important object of this invention' is to provide a process of drying macaroni and other articles such as cereals and including corn where# in the moisture is' effectively removed quickly and economically without impairing the quality of the articles.

Still another important object of this invention is to supply infra-red heat rays' in the drying of articles such as macaroni.

Another and further important object' of this invention is the provision of means in a drying process and apparatus for continuously removing moist air from the presencel of the articles being dried as they pass through the various stages'of drying. t

Another and still further importantV obj'eetof this invention is to provide a process* and" apparatus for drying macaroni or the like' in whichl several ovens are employed and employing various conditions of air circulating therein.

Still another and further important object of this invention is the provision of means.A in adry ing process to regulate the temperature of various ovens and the time through which articles are kept in these ovens; y t

Another important object` of this invention is tol 7 Claims.

provide a continuous process for drying moist macaroni without checking through a predetermined series of steps including a preliminary drier, an oven,v a sweat box, another oven, and finally cooling at room temperature.

Another object of this invention is thei provi-- sion of an oven having 'an infra-red. heating.

means and arranged to employ the heating. meansto pre-heat air to be subsequently circulatedover 2\ the articles being dried as they pass through the oven.

Other andfurther important objects of this invention will become apparent from the disclosures in the following specification and accompanying drawings.

In the drawings: A

Figure l is an elevational View of the drying apparatustpartially in schematic form.

Figure 2 is a top plan view of the preliminary drier as used in this apparatus. t

Figure 3 is a sectional View taken on the line 3-3 of Figure 2. t

Figure 4 is a top plan view of the first oven of thisv apparatus.

Figure 5 is a sectional line 5 5 of Figure 4.

Figure 6 is a sectional view ofthe sweat boit taken on line li--l of'Figre 1'.

Figure 7 is a top plan view of the second oven efIIlOyed l'this diy.

AS Shown ill' th drawings:

The rference n'll'l IU I"1t'iollisu gei'ily" a prelimmary drier or a heating unit having a trough-like container l2; with a conveyor r4 of screen material running therethrough. The' con- Vey01"S`0f the 'ICHS'S typ LiC is adapted 'O Carry" materialV through the trough the other'. The preliminary drier is equipped with a heating unit I6, prefe'rablyof the infra-red View of the oven taken on type 'and capable of attaining' a heat of approXi-- mately W". Although 15o*i is the desired tem perature, the preliurinary"v drier will operate effectively throughout a range 'of temperatures" from 100' to 20() Th"l5e1`m'iiiary'drei" adapted to beliung' yhariger brackets 2li from the ceiling" I8 of the room which the drying apparatus is installed; The bracketsdepend from the ceiling I8 and' entendaround'the bottom 'of the' trough l2 holding it in Hired position with respect to' the ceiling. The preliminary drier is` equipped'wlth an inlet zz'andan outlet 24'. lvlac'e.;`

roni `or other material to be -dried is delivered to' the preliminary drier through the inlet 22 andA thereupon the material moveaby means of tlie conveyor lill` along the-:trough |2. The" macaroni is sinrultaneously heated `by the'heatng unit die renting' its infra-redraw dow-n on the conveyor. During Vthe trai/'e1 of moist lfria-caronior other Inaterial Suclil as corn or the like, afan 26 is' adapted to directair fronr'tneroom over the inaterial carried byA the con' eyor.V Thusesecially inA the case of macaroniwliielr is'r we'tthroughout;

an outer surface or shell-like material is formed on the outside permitting vs''u-bseq'uerlt heat treat# ment aridha'ndlin'g without fear ithe'rnaterial sticking to' ovens olfotheifdevce's thlro'l'lgli which the material is to -loeAE passerl The preliminary drier is more or less a frlie'ans` for" qmekl heating. themacaroiii 'and forinirlgA this-outer sli f2' from one end td seared and doing it in a relatively short period of time. It has been found that a 11/2 minutes time period for the material to travel through the preliminary drier is suicient to dry the outer surface of the material and still eliminate any checking or cracking which has ordinarily accompanied quick drying of material such as macaroni. Although it is believed that 11/2 minutes is the most desirable period of time in which the material is to be in the preliminary drier, it is believed that a range of from a minute to two minutes is acceptable and under certain conditions other particular times within that range might prove to be more desirable.

It has been deemed advantageous to describe the complete process of the macaroni drier without immediately delving into the details of construction of each individual portion of the apparatus and thus we shall continue throughout the process and thereafter return to the more specific details of construction of the preliminary drier and also the following elements. The macaroni, after it has been flash dried in the preliminary drier, is discharged at the outlet 24 and passes downwardly through a conduit 28 to a first oven 30. The oven includes a deep tray-like container 32 and similarly to the preliminary drier has a heating unit 34 of the infra-red type capable of attaining a heat of 250 F. As in the case of the preliminary drier I6 the rst oven 30 may have a heat from 200 to 300 F., and still produce an acceptable drying of the macaroni. The 250 has been found to be very desirable, but under certain conditions and sizes of the macaroni some other temperature within this acceptable range of 200 to 300 might be employed. This rst oven 30 is equipped with a vibrator means 36, which by means of electricity causes the tray 32 to vibrate at any desired frequency to thereby cause the macaroni or other articles being dried to move from one end of the tray to the other. It should of course be understood that any type of conveyor means may be employed in this rst oven, and an endless conveyor of the type employed in the preliminary drier or the slatted type conveyor employed in a subsequent oven are equally acceptable. In order to complete the mounting of the oven on the vibrator means 36. a spring mounting 38 at the other end of the tray 32 is required. The spring 38 is carried on a floor engaging -leg 40. The floor of the room is designated by the numeral 42 and thus the oven 30 is supported on the floor. The oven 30 is equipped with an inlet 44 into which the conduit 28 passes material to be dried. The vibrator 36 is set in motion andthe material is moved along the tray 32 to an outlet 46. The desired length of time for the material to be in the rst oven 30 is 5% minutes. However, by experiment it has been found that the range of successful operation is from 4 to '1 minutes, and it is therefore a particular object of this invention to include in the coverage thereof the entire range of successful drying operation. It will be recalled that in the preliminary drier air was circulated over the material lying on the screen conveyor and that this air passing over the macaroni was air at room temperature. In the rst oven air is drawn in over the infra-red heating unit designated by the numeral 34 and after being pre-heated it is then blown down over the material in the deep tray 32 all by means of the combination fan and blower 48.

The material being dried, and in this case the macaroni, passes from the outlet 46 of the first Va discharge or outlet spout oven and is discharged into a enclosed sweat box 58. The sweat box is mounted on floor engaging legs 52 and is equipped with a canvas conveyor 54 which runs the length of the box at a very slow speed. The macaroni is deposited at an inlet 56 and drops onto the conveyor 54 whereupon it is moved over a. period of time to 58. The enclosed sweat box performs the function attributed to it by its name. The macaroni is permitted to sweat from the great heat applied in the rst oven 30 and the moisture comes to the surface of the macaroni. The length of time in the sweat box is preferably 20 minutes. However, it has been found through experiment that a range of time limits from approximately 10 minutes to 30 minutes is acceptable.

The macaroni, upon discharging from the outlet 58 of the sweat box, drops into a hopper 60, forming part of a blower and elevator mechanism. A blower 62 is adapted to force a current of air upwardly to an elevating conduit 64 which has communication with the hopper 60 in such a manner that the macaroni is carried upwardly through the conduit 64 on a current of air and deposited in a cyclone 66. The cyclone is a device for settling material entering therein with a mass of air. It is similar in effect to an expansion valve and thus the air is permitted to escape to an outlet in the top thereof and the heavier macaroni drops downwardly through a central portion thereof.

A second oven, 68, is provided with a slatted conveyor 16 and a heating unit 12 in the same manner as the preliminary drier and the first oven. Hangers 14 support the second oven from the ceiling I8. The second oven is further provided with an inlet 16 disposed immediately below the cyclone 66 and an outlet at the far end of the conveyor 10 as shown at 18. The heating unit is again of the infra-red type and is adapted to produce heat of approximately 250 F. Here again an acceptable range of temperatures is designated as from 200 to 300 F. The speed of the slatted conveyor 10 is similar to the speed of the vibrating conveyor of the first oven. It thus requires 51/2 minutes for the slatted conveyor 10 to move macaroni received at the inlet 16 to the outlet 18. This period of time may vary throughout an acceptable range of 4 to 7 minutes. In the case of this second oven there is no air circulation permitted over the macaroni as it is carried through this oven and in this respect it differs from both the preliminary drier and the first oven.

Upon completion of this cycle of operation the macaroni is now completely dried. However, it must be cooled in the following manner in order to eliminate spoilage that might be occasioned if it were to be immediately packaged. Thus the outlet 18 of the second oven is directly above a rst trough 80, which is exposed to the room in which the drying occurs, and is equipped with a conveyor 82 of the endless type adapted to run from one end of the trough to the other, and deliver macaroni from the inlet 84 to an outlet 86 at the end thereof. It should be understood that this conveyor 82 carries the heated macaroni from one end to the other thereof exposed to room atmosphere in order to facilitate cooling or bringing of the temperatures of the macaroni down to room temperature prior to packaging. The macaroni when it is discharged from the outlet 86 of the rst trough 80 falls into a second trough 88 having an endless conveyor 80 preferably ofthe canvas type, which runs from one end to the other of the trough 88. The macaroni falls into the inlet 92 'and is discharged atthe outlet 94e` Here again the conveyor is open to room atmosphere and thus permits the macaroni to cooland come down to 'the temperature of the room? The second trough 88 iis mountedon-oor engaging legs Sii and the `r'st trough 'is' carried on the second trough by means of spaced supports 98; The total length of time lin which the'im'ac'- arni iis on the conveyors 82 and Sq for most efficient cooling has been found to be twenty minutes. But, here again it lis possible to vary the length of time throughout a range of fro'ln to 30 'minutes without adverse effects and still effect a cooling of the macaroni 'to the required degree. The spout-like outlet 34 lis used to direct material dried to packages or the like for storage orfior later sale. The macaroni thus dried is free of checking and free of harmful moisture which would cause spoilage if the macaroni Were improperly dried.

VThe success of this drier has been accomplished bythe employment of a suction means designated bythe numeral |00 which hangs from the ceiling 1'8 by hanger brackets |02. The suction means'. is adapted to remove air and particularly moist air from the vicinity of the entire drying apparatus. Thus as the macaroni or other material being dried passes through the various stages ofthe drying mechanism, moist air that is `driven from the macaroni 'is drawn 'from the 'room imf Ined'iately upon its discharge from the macaroni and thus the atmosphere in which the drying takes 'place is relatively free of moisture loosened or "freed from the macaroni. This of course is conducive to a minimum of reattraction of the moisture for the macaroni through the last 'stages of the drying apparatus and particularly the second voven and the cooling room conveyors v82 and 190.

lIn order to more particularly designate the elements of this drying apparatus legends Vhave been incorporated on Figure 1 of the drawings in order to designate particular elements and arrows have been vemployed to show the path of travel of the 'macaroni during its dryingoperation.

:Figures 2 and 3 show in vdetail the construe-` tion of the preliminary drier designated 'by the numeral lo in Figure 1. I4 is maintained 'in spaced apart position by rollers It!! and lot journaled for rotatiomin extreme "ends of the preliminary drier trough-like container l2. Throughout the drawings there has been Vno means showin to drive the endless conveyors or fans and it should be explained that external motor means or belting from some pow-er source is provided to impart proper rotation and drive to these elements. In the case of the preliminary drier the conveyor Ill composed of screen or grid material moves from a position adjacent the inlet 22 along the pan l'I2-to the "ou-te let 2. Thus material entering the inlet drops on to `the mesh conveyor and is carried thereby to the discharge of the preliminary dryer. Dure ing its travel along this 'pan "|22 the material, and in this case macaroni, is subjected to forced currents of air at room temperature. The pan'or trough I2 is provided with lateral side conduits |8 and Iii?. Vjr`Ihe conduit EIIi is provided with a series of spaced openings I I2 entering vthe trough `I2 over the conveyor I4. The fan ZBUjoi-ns the conduit I |33 as shown in Figures 2 and l3, and draws air at room temperature therein and dis# perses it along the conduit M18 `.whereupon it 'is The screen c'or'iveycr top oiv the conveyor I4. The corresponding con-V duit II'U on the opposite side of the tray I2 is similarly equipped with spaced apertures ||4 which are offset from the openings I I2 in the conduit |68, whereupon currents of air entering atl I I2 are required to 'move longitudinally of the drier in order to iind one of the air outletsl'l in the elongated lateral sideconduit I I0. As best shown inl Figures 2 and 3 the fan 'is provided with an opening |I6 to the room atmosphere in order to draw air therein. The discharge of the air after it passes over the macaroni to be dried is out the ends H8 of the conduit Hi). It should thus be realized that the air passing over the macaroni in the preliminary drier is air in which the moisture is continuously removed by reason ofthe suction means |00. This is conducive to quicl extraction of surface moisture on the macaron'i." The preliminary drier is therefore vprimarilylfor the purpose of removing surface mois ture and conditioning the macaroni for future more intense heating and drying of the interior thereof.

The -first oven 30 has its heating unit 34 divided into upper and lower chambers by means of a partition |20 disposed intermediate the top and bottom of the -heating unit 34. The upper chaine ber formed by the partition |25 is `designated by the' numeral IZI and is open at one end of the rstoven 3i)l at |22 for admission of room air therethrough. The chamber I2! is thus parti-ally heated by the upper sides of the infra-red heating unit. The combination fan and blower d'8 lis adapted to draw air through the opening |22.;v A conduit |24 completes the 'path ci travel from the air inlet |22 through the chamber |2I to the fan and blower 48 as best shown in Figure 4.. The drawing of air at room temperature through the chamber |2| causes the air to be' pre-heated and in the combination fan and blower the 'pre-heated air is forced outwardly through the Vesha'ped conduit |26, thus delivering this preheated air to laterally spaced side conduits |218 and |30. The V-s'haped conduit |26 directly joins the cross 'conduit |32 which has communication with both of the side conduits |23 and |-3'Il. Yris' the pre-heated air 'is passed down the side -fconduit 1.28 it is discharged through longitudinally 'spaced nozzles i3d, thus directing hot ai-ro'ver the macaroni 'moving through the deep tray 32 ofthe first 'oven 30. Similarly spaced nozzles |36 offset from the nozzles |34 are located in the conduit |30 and direct lhot air onto the macaroni in the deep tray 32 from the oppo'siteside. The fnrst oven thus distinguishes materially from the preliminary drier, first in that the temperature is considerably higher, and second, 'the macaroni is maintained within the ovenfor a considerably longer period of time, and

third, thecurrent's of air directed over the maca' reni to b'e dried is pre-heated, and thus in combination with the infra-red type of heating Vunit the macaroni is dried or heated `on the inside, tending to draw and drive moisture out from the interior of the macaroni pieces. The detailed'. construction of the first voven as just described is shown .in Figures l and 5.

`liligure 6 shows a sectional `viewof the sweat box employed in this apparatus immediately vfollowing exit of the macaroni from the nrst oven. The conveyor `154 is of the-endless 'canvas type and is provided with spaced rollers |38 and VvIll-3 over which. the 'canvas is draped for proper vspacing and driving thereon The rollers are journal-edI within the sides of the sweat box 50. The sweat box is provided with a top |42 hinged at |44 to permit access to the interior thereof. However, in operation the sweat box remains closed and the macaroni is permitted to sweat so that the heat imparted thereto by the first oven causes the internal moisture to come to the outer surface.

'I'he macaroni then drops into the hopper 60 from the enclosed sweat box and the blower 62 carries the macaroni on a cushion of air up through the conduit 64 to the cyclone 66. Inasmuch as the macaroni was permitted to sweat or have its moisture come to the surface, this air by which the material is blown upwardly to the cyclone tends to drive oi portions of the surface moisture and when the macaroni drops from the cyclone to the second oven it is ready to assume or assimilate the heat provided by the infra-red heating unit 12. The second oven is best shown in Figures 7 and 8, in which the conveyor 10 is provided with spaced rollers |46 and |48. These rollers are equipped with laterally spaced sprockets |50 and |52 over which the slatted conveyor 10 is adapted to be run and driven. Cross bars |54 join chain elements of the conveyor 10 and cooperate with the bottom |56 of the tray or elongated pan of the second oven and thus act as an undershot feeder for delivering macaroni from one end of the oven to the other. Various types of conveyors have been shown in the preliminary drier and the srt oven as well as the enclosed sweat box. It should be understood that any one type of conveyor may be effectively employed or several types may be employed as shown without interfering with the successful operation of the entire apparatus.

The device thus described is a new apparatus for the effective drying of macaroni without impairing the quality thereof. Further, the drier may be employed for drying cereals such as corn in the same manner. In the drying of articles which do not have excessive surface moisture the preliminary drier might possibly be eliminated. The device of this invention has been found to be particularly effective in the drying of corn following its picking from the field. In order to store corn or other grains safely it is necessary that its moisture content be some predetermined maximum and if :it is above that amount when picked when it is necessary to dry the corn artificially by means such as the drier of this invention. The corn reacts in the same manner as the macaroni and although it is not necessary to employ the preliminary drier in the drying of corn, the remainder of the apparatus and process is identical.

Numerous details of construction may be varied throughout a wide range without departing from the `principles disclosed herein, and I therefore do not propose limiting the patent granted hereon otherwise than as necessitated by the appended claims.

What is claimed is:

l. A macaroni drying process comprising the steps of preliminarily heating macaroni to be dried at a temperature range of 100 to 200 F. for a period of one to two minutes, heating the preliminarily heated macaroni at a temperature range of 200 to 300 F. for a period of four to seven minutes, thereafter passing the macaroni to be dried through an enclosed sweating chamber for a period of ten to twenty-five minutes, and then heating the macaroni to be dried at a.

temperature range of 200 to 300 F. for a period of four to seven minutes.

2. A macaroni drying process comprising the steps of preliminarily heating macaroni to be dried at a temperature range of to 200 F. in an atmosphere of moving room air for a period of one to two minutes, heating the preliminarily dried macaroni at a temperature range of 200 to 300 F. in an atmosphere of moving pre-heated air for a period of four to seven minutes, thereafter passing the macaroni to be dried through an enclosed sweating chamber for a period of ten to twenty-five minutes, and then heating the macaroni to be dried at a, temperature range of 200 to 300 F. in an atmosphere of stationary air for a period of four to seven minutes.

3. A process as set forth in claim 2 in which a suction is placed on the room in which' the drying occurs whereby moist air is continuously withdrawn from the presence of the dryingmacaroni.

4. An article drying apparatus comprising a preliminary drier maintained at temperatures between the range of 100 to 200 F., means for passing articles to be dried through said preliminary drier over a period of about one to two minutes, an oven maintained at temperatures between the range of 200 to 300 F., means forv moving articles to be dried from said preliminary drier through said oven over a period of about 4 to 7 minutes. an enclosed sweat box for said articles to be dried, means for moving articles to be dried from said oven through said sweat box over a period of about 10 to 25 minutes, a second oven maintained at temperatures between the range of 200 to 300 F., and means for moving said articles to be dried from said sweat box through said second'oven ov-er a period of about 4 to 7 minutes.

5. An article drying apparatus comprising a preliminary drier, heating means therefor, a conveyor in said preliminary drier adapted to convey articles therethrough, fan means arranged and constructed to circulate room air through said preliminary drier, a rst oven, heatingv means therefor, means for conveying articles through said first oven, suction means for drawing room air over said rl'lrst oven heating means separable.

from said articles for preheating said air, and means for blowing said preheated air over the articles within said first oven, an enclosed sweat box, a conveyor for carrying articles through said sweat box, a second oven, heating means therefor, and a conveyor in said second oven for moving articles therethrough.

6. An apparatus as set forth in claim 5 in which suction means is positioned adjacent the apparatus and arranged and constructed to continuously take moist air away from the presence of the drying apparatus.

'7. An apparatus as set forth in claim 5 in which combination blower and cyclone means is provided for delivering articles from the sweat box to the second oven.

BAYARD S. SCOTLAND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,822,313 Quiggle et al Sept. 8, 1931 2,074,458 Cavagnaro Mar. 23, 1937 2,259,963 Surico Oct. 21, 1941 2,466,130 Surico Apr. 5, 1949 

